Image projection device

Abstract

An image projection device is configured to project a display image on an image display board, formation of an unnecessary image in a peripheral area of the display image due to generation of stray light is effectively suppressed. A plurality of columnar protrusions is formed on an inner surface of a housing in which an image generation unit that generates the display image is housed, and a second columnar protrusion having a lower height than each of the plurality of the columnar protrusions is formed. That is, even when a part of emitted light from the image generation unit, sunlight, etc. reach the inner surface of the housing, the light that has reached the inner surface is reflected multiple times between the plurality of the columnar protrusions and between the plurality of the columnar protrusions and the second columnar protrusions, which can effectively attenuate intensity of the light.

1 . An image projection device configured to project a display image on an image display board, the image projection device comprising:
 an image generation unit that is configured to generates the display image; and   a housing that accommodates the image generation unit, wherein   a plurality of columnar protrusions is formed on an inner surface of the housing, and   a second columnar protrusion having a lower height than each of the plurality of the columnar protrusions is formed between the plurality of the columnar protrusions.   
     
     
         2 . The image projection device according to  claim 1 , wherein a ratio between a pitch between the plurality of the columnar protrusions and a height of each of the plurality of the columnar protrusions is set to a value of 1.5 or less. 
     
     
         3 . The image projection device according to  claim 1 , wherein
 a pitch between the plurality of the columnar protrusions is set to a value of 200 μm or less; and   a height of each of the plurality of the columnar protrusions is set to a value of 50 μm or more.   
     
     
         4 . The image projection device according to  claim 1 , wherein the housing is made of a resin molded product in which carbon black is dispersed. 
     
     
         5 . The image projection device according to  claim 1 , wherein a reflecting mirror that reflects light emitted from the image generation unit toward the image display board is disposed in the housing.